Answer to Question #247159 in Geometry for beza

Question

If the circle passing through the point (-1,0) touches the y-axis at (0,2) then what is the equation of the circle?

Answer 1

Since the required circle touches y-axis at (0,2) and let r be the radius of the circle.

So, the center will be (−r,2).

Equation of circle is

(x+r)²+(y−2)²=r²

Since, it passes through (−1,0),

⇒(r−1)²+4=r²

⇒r=5/2

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So, the equation of the circle:

(x+5/2)²+(y−2)²=25/4